IDH1 and glioma: The recent WHO classification, 5th Edition13, classifies these as a) Diffuse midline glioma, H3 K27-altered, WHO grade 4 b) Diffuse hemispheric glioma, H3 G34-mutant, WHO grade 4 c) Diffuse pediatric-type high-grade glioma, H3-wildtype and IDH-wildtype, WHO grade 3 or 4 d) Infant-type hemispheric glioma, WHO grade 4.